The Ryu Ga gotoku 6 Perfect Capture Guide from famitsu is now available to purchase both physically and digitally. You can grab it from Amazon and is as much a guide as it is a complete game encyclopedia.
Looks like they didn’t miss anything! The first 40 pages of the guide are below as a preview of the quality you can expect if you pick it up.
It’s a shame there wasn’t any extra interviews or info about the making of the game included but as a companion piece for anyone that wants to know everything about Yakuza 6 it’s a nice addition.